How Dangerous Is A Cottonmouth Snake?

You’ve heard that cottonmouths have dangerous bites, but how concerned should you be, really? How dangerous is a cottonmouth snake? Can its bite kill you? Leave you scarred and maimed? What should you do if you are bitten by a cottonmouth? Keep reading! In this article, we’ll answer all of these questions and more! 

How Venomous is a Cottonmouth Snake?

how venomous is a cottonmouth snake

Cottonmouth snakes are pit vipers, and like all pit vipers, they are venomous. They can inject this venom into prey and predator alike, quickly killing their next meal and causing serious injuries to larger bite victims such as humans.

That said, cottonmouth venom causes less than one percent of snake bite deaths in the U.S. Though their venom can kill, seeking immediate medical attention after being bitten greatly reduces your chances of death.

Cottonmouth venom is thought to be more dangerous than the venom of copperhead snakes, another type of pit viper. That said, the most well-known pit vipers, rattlesnakes, are far more deadly than both copperheads and cottonmouths.

What’s more, cottonmouths are not known for being aggressive. They will sometimes stand their ground and go into a fighting stance when they are threatened, but more often than not, they prefer to run away rather than bite, as you can see in the following video:

What Happens if You Get Bit By a Cottonmouth Snake?

Despite being naturally unaggressive, cottonmouths do occasionally bite humans. They will bite if you step on them or try to handle them.

Cottonmouth venom is cytotoxic, which means it destroys living cells wherever it spreads throughout the body. It is particularly known for destroying the cells of blood and blood vessels, preventing the blood from clotting correctly.

As a result, cottonmouth bites can cause significant bleeding, both internally and externally. They can also cause muscle damage and death to other tissues; if left untreated, they can even cause gangrene and necessitate amputation of the affected limb.

If you are allergic to cottonmouth venom, you may experience an anaphylactic reaction, which can cause death from airway constriction and shock. Though these reactions are rare, it is good to be aware of the possibility, especially if you are allergic to other types of snake and insect venom and aren’t sure how your body will react to a cottonmouth bite.

Even if you don’t have an allergic reaction to cottonmouth venom, you will likely experience a severe, stinging pain at the wound site. The area around the bite will soon begin to swell and blood may drain continuously from the bite wounds.

This is the time to seek medical attention; the sooner you can receive antivenom treatments, the better your chances of making a complete recovery.

If you don’t get to the hospital right away, the venom will continue to spread, causing blood tissue damage wherever it goes. The longer the bite is left untreated, the more likely you are to sustain irreversible damage to blood vessels and limbs.

If enough venom is injected, or if it spreads to the vital organs of your body, it can lead to organ failure, massive internal bleeding, and death.

How Fast is a Cottonmouth Snake?

Cottonmouths can move swiftly both on land and through the water. Though they are most likely going to move away from you if they feel threatened, you should keep in mind that, if they do decide to bite you, they can strike very suddenly.

In fact, the cottonmouth has one of the fastest striking times of any pit viper. If it decides to strike, it will move a distance of nearly three meters per second as it launches itself toward its victim.

With this in mind, it’s best to stay well away from cottonmouths as much as possible. Give them plenty of space to avoid inadvertently threatening them into feeling the need to strike you.

What to Do When You See a Cottonmouth Snake?

what to do when see a cottonmouth snake

Cottonmouths are a common sight throughout much of the southern and eastern parts of the U.S., from Texas to Florida and northward to Virginia, Illinois, and Indiana. If you live anywhere in this region and you come across a cottonmouth, the best thing you can do is give it space.

You don’t have to worry if you are on a bridge, for example, and you see a cottonmouth swimming along in the stream below. You are far enough away to avoid being seen as a threat, and the snake has no desire to pick a fight with a much larger creature.

But if you’re trekking through a swampy environment, you may stumble upon a cottonmouth by accident. In this case, you may not see the snake until the moment before it strikes you.

If you are getting too close to a cottonmouth, it will likely coil its body into a fighting posture, shake its tail, and open its mouth wide. It may make hissing noises and may emit a bad-smelling odor much as a skunk might do.

If you see a cottonmouth displaying any of these behaviors, run away from it immediately. Put as much distance as possible between yourself and the snake, and do so quickly to avoid being bitten.

If a cottonmouth gets inside your house or is taking up residence in your yard, you may need to call a professional wildlife service to have the snake removed. Never try to handle a cottonmouth yourself unless you have been trained on proper snake handling methods.

Regardless of the particular circumstances, the best thing you can do whenever you see a cottonmouth is to simply give it space. If you avoid getting too close, it will go on about its own business and leave you alone.

How to Avoid Cottonmouth Snakes

If you live in a region where cottonmouths are common, it may be impossible to avoid them completely. However, there are a few things you can do to limit your chances of seeing them:

  • Avoid wetland habitats: You’re most likely to spot these snakes in and around water. With that in mind, stay away from swamps, ponds, marshes, creeks, streams, and even drainage ditches.
  • Seal your house: To keep cottonmouths from getting into your house, make sure your foundation is sealed and that there are no gaps under your doors or windows. Fix any broken windows, cracked walls, and other openings where snakes could get inside.
  • Invest in a snake fence: To prevent cottonmouths from coming inside your yard, you could place a snake fence around the perimeter. These short fences have very small gaps that snakes can’t slither through, so they provide an effective barrier as long as they go all the way around your yard.


Cottonmouth snakes are highly venomous snakes, and though their bite probably won’t kill you, it can cause major and irreversible tissue damage. To make a full recovery and prevent long-term complications, you should seek medical attention right away if you suspect you’ve been bitten by a cottonmouth.

Here’s our guide with snakes that are similar to cottonmouths and can be therefore confused.

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